Gillian Thornton

Hello to anyone who has happened across my blog. Thanks for visiting The PTSDetails: Brain Plasticity and Chronic Stress. This is where I will be documenting my progress through my Senior Project. An explanation of my project can be found in my Senior Project Proposal but I’ll do my best to introduce you to it briefly in this blog post.

As a BASIS Scottsdale senior, I will be going off campus during the third trimester of school (from around February 6^th to April 14^th) and interning in a lab at ASU. I am lucky to be working in Dr. Cheryl Conrad’s lab, Behavioral Neuroscience Research in Stress. The purpose of their research is to look at inhibitory cellular circuitry on chronic stress and resilience. Working towards this goal, Dr. Conrad and her team have published many research papers (a good chunk of which are available on their website which I have linked above).

Before my initial interview I read one that I found particularly interesting titled “Chronic stress enhanced fear memories are associated with increased amygdala zif268 mRNA expression and are resistant to reconsolidation.” The title sounds quite scary (and I commend you if you made it through the whole thing) but how I’d summarize it is they studied rat models for PTSD, pairing Pavlovian fear conditioning with chronic stress, to investigate the mechanisms underlying fear memory formation, extinction, and re-consolidation. They hoped to understand how a robust fear memory can be weakened so that a previously traumatic memory can become less distressing. I’d really recommend checking out that research paper if you’d like to get an idea of the work they will be doing while I’m interning.

Now, more specifically about me, my main activities as an intern (exactly as they were documented in order to be approved to work in the lab) will be working closely with a graduate student, picking up, holding, and weighing mice, assisting putting mice in restraints, cutting perfused and fixed brain, and using a microscope to look at brain slices. So what does that mean exactly? Basically, I’m going to be helping out when and wherever needed and absorbing as much experience as I can. This will be my first real time in a lab so I am really excited to get started and am happy that I will be able to document my thought process as I go along.

I’ve always been really interested in Biology and Psychology. And, being a high school student, I’ve had my fair share of stress. Throughout my high school career I have found that knowing your optimal stress balance is essential to succeeding (you want enough so that you are driven to work hard, but not too much so that you avoid burning out). Therefore, working in a lab that focuses primarily on stress coincides perfectly with my interests. I’m really excited to begin, and, if you’d like to follow along, feel free to subscribe by email to receive updates (a gadget to do so is off to the side). Thanks for reading!

Week 10

Welcome to the last week of the senior projects! I can’t believe it’s here already.

Coinciding perfectly with the end of my senior project, the lab finished up a lot of projects that they have been working on. On Monday, I helped Bryce weigh the mice used in his study for the last time. He is done stressing the mice and will now analyze the impact that chronic stress had on proteins in their brains. An undergraduate students also helped me check the data from the aging and stress study that I put into Excel. We need to ensure that I transferred the right numbers and didn’t make any typos.

On Wednesday, since I finished up the study that I was working on, I helped with another study. For this study, rats are placed in a maze with three arms. The first time they are placed in the maze, an arm is blocked off. The second time, the arm is opened up. They are looking to see how much time the rat spends in this novel arm compared to the start and other arm. I was doing a lot of math in order to determine that for the remaining rats.

Today is Friday, and our lab meeting is a little different than usual. We are combining with another lab to listen to a guest speaker talk about sex hormone influences on cognition. I’m excited to see what the meeting is like.

For the rest of the project, I just need to practice my final presentation. Presenting it at last week’s meeting was really helpful, and I feel very confident talking about it now.

Looking back, I’m really glad that I got this opportunity as I am going to be able to continue with the lab in college. I came into this thinking I wouldn’t enjoy the research side of psychology as much as I did. It’s changed my perspective on working in a lab, and I’m excited to continue doing so. Overall, I would say that the senior project is a great way to explore new things even if they aren’t what you picture yourself doing as a career. Be open to all the potential site placements that come your way.

Finally, I would like to thank everyone that I’ve worked with: Dr. Conrad, Bryce Ortiz, everyone else at her lab Behavioral Neuroscience Research in Stress, my college counselors, my friends and family, and everyone who has been following along and reading my posts. Thanks so much!

Week 9

Welcome to week 9! I can’t believe there’s only one week left.

I came into lab Monday, Wednesday, and Friday as I usually do. However, this week was especially eventful and stressful (at least for me).

Monday was my first time actually working with mice. Bryce needed help weighing and restraining them, so he taught me how to. The mice are housed in a different building, so, after making our way over, we put on our PPE (personal protective equipment). You need to wear a mask, gloves, and a robe of sorts before handling the mice. The mice are housed based on cohort (or litter) with each one having their own cage. Within each cohort there are about three or four mice. Each litter has a mouse in the control, stress immediate, and stress recovery groups. There is a sharpie mark on their tail indicating which is which. Our task for the day was to weigh and restrain the stress immediate mice.

We separated them from the other mice and placed them in cages that could be transported between rooms. First, we weighed the mice. You pick them up by the base of their tail and place them on a scale. We keep track of their weight in order to prove the validity of using restraint as a stressor. Under periods of chronic stress, the animals should lose weight. Second, we restrained the mice. This is the part that I was most worried about as I didn’t know if the mice would struggle or show any signs of distress. That would’ve been sad to see. However, the rats experience no pain and go into the restraints relatively easily. You simply place their heads near the opening and scoop them into the mesh wire cage. You then close off the end, making sure not to pinch their tails. The mice don’t struggle and are put under no unnecessary stress.

Wednesday I worked a lot on my PowerPoint as I needed to meet with Dr. Conrad that day to go over it. Bryce reviewed it in the morning and sent me some pictures that would be helpful to include. After completing it to the best of my ability (I still needed to discuss the analysis of the graphs that I had created with Bryce), I went to meet with Dr. Conrad. I wasn’t as ready as I should’ve been, but she was very kind and very helpful, pointing out everything that I should work on before presenting it in lab meeting.

Today is Friday and I’m going to be presenting in little less than an hour. It’s going to be structured much like the talks that the undergraduate students gave in previous meetings. I’m going to present for around ten minutes, and the rest of the time will be used for comments. Hopefully this will help me be really prepared for the final presentation.

Thanks for following along!

Week 8

Welcome back for week 8!

I went into lab Monday, Wednesday, and Thursday this week. Friday is my birthday so I decided to take it off (:

On Monday and Wednesday, I searched for a few more articles for Bryce, but I mostly helped make mice restraints. I made 20 of them. First, I had to cut the proper dimensions from a roll of wire mesh. Second, I folded the sheets into restraint shapes. Third, I covered all the exposed edges with a sort of liquid rubber that will dry and ensure that the restraints stay together. As I said in response to some comments last week, I believe that these restraints are to prepare for the fear conditioning study that will be taking place over the summer. That study will be branching off the one that I mentioned in my introductory post. Basically, the lab pairs chronic stress with fear conditioning to create a rat model of PTSD.

On Thursday (which is the day I am writing this), I met with Dr. Conrad and Bryce to discuss the end of the Senior Project. They are going to help me with my final presentation. I am going to present to Bryce on Monday and Dr. Conrad on Wednesday and they will give me some pointers before I present to the entire lab Friday. Needless to say, I’m quite nervous and really need to get a move on with this PowerPoint.

Dr. Conrad gave me some brief pointers in the meeting today, and I am going to note them down here. As you all know, I have been working on the aging and stress study. Dr. Conrad wants me to give background on the study (things like what are dendrites, why are we looking at the hippocampus, why is chronic stress different from normal stress, etc.) I’ll then introduce the study, present the raw data, and explain the graphs that I made. They also said that my name will be on a poster when the study is formally presented. So that’s pretty exciting.

Now, I want to quickly give an overview of what I will be doing for the last two weeks of my project. Next week will mostly be working on and presenting the final presentation to the lab. The week after that I will take all the comments and improve the PowerPoint. I hope to have it well polished by the time it is due to BASIS for review.

Thanks for following along! The Senior Project is coming to a close much faster than I thought it would.

Week 7

Welcome to my week 7 blogpost!

This week I finished up the aging and stress study. I had everything grouped in Excel and transferred it over to a program called Prism. Prism is a program that graphs data. I made a total of 6 graphs. The x-axis of the graph is distance away from the cell body of the neurons, and the y-axis is the amount of breaks in the dendrites. I graphed the mean value for the SS, the LS, and the combined SS and LS neurons for both young and old mice. I have yet to analyze what the graphs show but plan to first check the numbers that I have entered and to then draw conclusions with the help of Bryce. I hope to also post pictures of the graphs but I’ll need to double check that I am allowed to do that.

Since I have been working on the aging and stress study and not on the fear conditioning study that I had anticipated, I am going to need to change my research question. Initially, I was going to focus primarily on PTSD but am going to make my research question a bit more general. Simply, what is the impact of chronic stress and can one recover from it? I am going to use the aging and stress study to talk about the impact it has on different ages. I will also have to do a lot of research surrounding the chronic stress and the recovery from it.

I have been helping the graduate student I am working under, Bryce, find articles to cite in a paper he is working on. So Wednesday was primarily spent scouring Google Scholar. I used search terms such as chronic stress, resilience, recovery, spatial memory, and dendritic retraction. I read through the abstracts of the paper to ensure that they would be of use in Bryce’s paper. In addition, a not so fun but a necessary fact if you’re going to be looking at a lot of articles, is most articles have an IMO which is a group of letters and numbers used to identify the work. If you put the IMO into a search engine it’ll pull up the exact article. I don’t know how I went so long without knowing that considering I’ve done a fair amount of research throughout my high school career. I plan to look more thoroughly at these papers and hopefully use them in my presentation as well.

Thanks for reading!

Spring Break!

Week 5

Welcome to Week 5!

I went into lab Monday, Wednesday, and Friday this week. This week was ASU’s Spring Break, but I decided to come in anyways as many students in the lab were too.

On Monday, I worked on Excel. In case you missed the explanation of what I’m doing in my previous posts, I’m putting all the numbers that I got from Sholl Analysis into a spreadsheet so that we can graph the data. Sorry that’s not too interesting to read about. I’ve been trying to think of more to write, so if there’s any part of working in a lab that you want to hear more about please let me know. In other news, I also figured out where Dutch is in relation to the Psychology building so that makes going to Tempe a little more exciting.

On Wednesday, I worked more on Excel. I also found out that I don’t know how to turn on a Mac desktop computer. I was sitting all alone in lab frantically searching for the power button (which by the way was not on the back of the display as Google had promised) so that no one would know. Unfortunately, one of the students came in, and I had to ask for her help. I also had to ask for the password, so I’m telling myself that, even if I did know how to turn on the computer, I wouldn’t have been able to sign in. So it’s fine.

After that little incident, I finished putting everything in Excel. Thinking I was free, I told the graduate student, Bryce, that I was finished. He seemed very happy with my progress but told me I need to further organize the data, making different pages in the Excel document. Got to admit, I really like organizing and color coding, so I enjoyed this a bit more than I thought I would. Bryce helped with this and told me a little more about the study (or at least the parts of the brain that the study focuses on).

As some background, I am working on the aging and stress study which looks at the impact of chronic stress in old compared to young mice. They are looking at the hippocampus in both groups, specifically the CA3 region. Here’s a picture:

In this region, there are primarily pyramidal neurons which have an apical portion extending from the top and a basal portion extending from the bottom. On the apical portion, if there is only one dendrite extending for a while away from the cell body, the neuron is a long shaft (LS) neuron. If this dendrite branches shortly after leaving the cell body, the neuron is a short shaft (SS) neuron. I’ll include an image of a pyramidal neuron but, unfortunately, couldn’t find one comparing LS and SS neurons.

On Friday, Bryce was out sick, but I finished putting everything in Excel. I had to further organize the rats based on their group (control, stress immediate, or stress recovery). The control rats were not stressed. The stress immediate rats were euthanized immediately after being chronically stressed. The stress recovery rats were given a period of time to recover after being chronically stressed and were then euthanized. I also grouped each rat’s neurons depending on if they were LS or SS. The next step will be graphing all this data.

I hope everyone who was on Spring Break had a great vacation! I am planning to take my Spring Break next week. Thanks for reading!